1. Field of the Invention
The present invention relates to a memory card using, for example, a NAND flash memory, and a method of controlling the memory card at a starting time.
2. Description of the Related Art
In a system in which a NAND flash memory is used, data of each block in the memory needs to be scanned at a system starting time to obtain various types of information. This information includes information on whether or not the block is a block (hereinafter referred to as the bad block) having an error or whether or not the block is a vacant block, information indicating a logical block address of written data and the like. However, in recent years, a technology has been considered in which a centralized management block to manage this information in a centralized manner is disposed in the memory, and various types of information in all the blocks in the memory are written together beforehand in this centralized management block (see, e.g., Jpn. Pat. Appln. KOKAI Publication No. 9-198884).
When this centralized management block is disposed, the centralized management block is detected at the starting time, and the data is read from this centralized management block. Consequently, it is possible to obtain the information of the whole memory without scanning all the blocks in the memory.
However, when an uncorrectable error is generated at the time of reading the centralized management block, and the information of the centralized management block cannot be read, it is impossible to start the system. In this case, it is difficult to use the memory card, although most of the blocks are normal. This is therefore very inconvenient for a user. Therefore, there has been a demand for a memory card in which the system can be securely started even in a case where there is an error in the centralized management block, and a method of controlling the card.